189-528: Llullaillaco ( Spanish pronunciation: [ʎuʎajˈʎako] ) is a dormant stratovolcano on the border between Argentina ( Salta Province ) and Chile ( Antofagasta Region ). It lies in the Puna de Atacama , a region of tall volcanic peaks on a high plateau close to the Atacama Desert , one of the driest places in the world. Its maximum elevation is most commonly given as 6723 m , making it
378-480: A tambo (inn) at an altitude of 5200 m on the northeastern flank. The tambo consists of numerous buildings; it was probably a base camp for ascents. On the road from Salar de Llullaillaco is a cemetery , where 16 bodies were found in 1972. The cemetery may host the bodies of people killed in the construction of the Llullaillaco archaeological sites. Half-destroyed walls form a building complex, which
567-413: A 3 km long deposit of lava blocks and pyroclastic pumice , with fallout reaching Cerro Rosado. It is possible that some lava flows interacted with glaciers , causing them to melt, and volcanic rocks overran glacial and periglacial landforms. The oldest dated rocks at Llullaillaco were erupted 1.5 ± 0.4 million years ago, forming a lava flow northwest of Llullaillaco's main edifice. Llullaillaco I
756-648: A ghost town ) and Fourpeaked Mountain in Alaska, which, before its September 2006 eruption, had not erupted since before 8000 BCE. Mars Mars is the fourth planet from the Sun . The surface of Mars is orange-red because it is covered in iron(III) oxide dust, giving it the nickname " the Red Planet ". Mars is among the brightest objects in Earth's sky , and its high-contrast albedo features have made it
945-636: A protected area created in 1995 and named after the mountain. Air pollution from the Escondida copper mine may reach Llullaillaco and threaten ecosystems there. In the 1950s a number of archaeological sites were discovered on Llullaillaco. After the initial discovery in 1952, further expeditions by various researchers and organizations took place in 1953, 1954, 1958, 1961, 1974, 1983, 1984, 1985 and 1993. Some sites were looted after their discovery. Three Inca roads come to Llullaillaco from Salar de Llullaillaco, Salar de Punta Negra and Socompa, and meet at
1134-446: A cave on Llullaillaco is doubtful. The edifice covers an elliptical area of 23 km × 17 km with about 37 cubic kilometres (8.9 cu mi)-50 cubic kilometres (12 cu mi) of volcanic rock. The ground at Llullaillaco is formed mostly by lavic rocks and block debris, which are frequently buried by tephra . The rocks are grey, except where weathering has coloured them black, brown, red or yellow, and their appearance
1323-489: A classical albedo feature it contains. In April 2023, The New York Times reported an updated global map of Mars based on images from the Hope spacecraft . A related, but much more detailed, global Mars map was released by NASA on 16 April 2023. The vast upland region Tharsis contains several massive volcanoes, which include the shield volcano Olympus Mons . The edifice is over 600 km (370 mi) wide. Because
1512-583: A common subject for telescope viewing. It is classified as a terrestrial planet and is the second smallest of the Solar System 's planets with a diameter of 6,779 km (4,212 mi). In terms of orbital motion, a Martian solar day ( sol ) is equal to 24.6 hours, and a Martian solar year is equal to 1.88 Earth years (687 Earth days). Mars has two natural satellites that are small and irregular in shape: Phobos and Deimos . The relatively flat plains in northern parts of Mars strongly contrast with
1701-416: A composition similar to Llullaillaco II are found on the southern slope of the volcano and may have formed before the lava eruptions began. An older unit is formed by ignimbrites and pyroclastic flows . Older lava flows extend west from the volcano and are partly buried by sediments closer to the edifice. The landslide probably took place during an eruption. An explosive eruption of Llullaillaco II produced
1890-578: A consequence of the dry climate, as the high insolation and dry air cause all snow to evaporate before it can form glaciers. However, Llullaillaco has permanent snow fields in protected niches, which are not large enough to give rise to glaciers. 1–1.5 m high penitentes occur above 5000 m altitude, especially in more sheltered areas and around the old crater. The snowline lies at 5400–5800 m elevation. Temporary snow cover also occurs. The snow and icefields on Llullaillaco reach thicknesses of 7–10 metres (23–33 ft) and supply water to
2079-422: A global magnetic field, the types and distribution of auroras there differ from those on Earth; rather than being mostly restricted to polar regions as is the case on Earth, a Martian aurora can encompass the planet. In September 2017, NASA reported radiation levels on the surface of the planet Mars were temporarily doubled , and were associated with an aurora 25 times brighter than any observed earlier, due to
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#17327765831782268-437: A graduated spectrum, with much overlap between categories, and does not always fit neatly into only one of these three separate categories. The USGS defines a volcano as "erupting" whenever the ejection of magma from any point on the volcano is visible, including visible magma still contained within the walls of the summit crater. While there is no international consensus among volcanologists on how to define an active volcano,
2457-488: A high ratio of deuterium in Gale Crater , though not significantly high enough to suggest the former presence of an ocean. Other scientists caution that these results have not been confirmed, and point out that Martian climate models have not yet shown that the planet was warm enough in the past to support bodies of liquid water. Near the northern polar cap is the 81.4 kilometres (50.6 mi) wide Korolev Crater , which
2646-490: A low of 30 Pa (0.0044 psi ) on Olympus Mons to over 1,155 Pa (0.1675 psi) in Hellas Planitia , with a mean pressure at the surface level of 600 Pa (0.087 psi). The highest atmospheric density on Mars is equal to that found 35 kilometres (22 mi) above Earth's surface. The resulting mean surface pressure is only 0.6% of Earth's 101.3 kPa (14.69 psi). The scale height of
2835-442: A massive, and unexpected, solar storm in the middle of the month. Mars has seasons, alternating between its northern and southern hemispheres, similar to on Earth. Additionally the orbit of Mars has, compared to Earth's, a large eccentricity and approaches perihelion when it is summer in its southern hemisphere and winter in its northern, and aphelion when it is winter in its southern hemisphere and summer in its northern. As
3024-542: A minimum thickness of 6 kilometres (3.7 mi) in Isidis Planitia , and a maximum thickness of 117 kilometres (73 mi) in the southern Tharsis plateau. For comparison, Earth's crust averages 27.3 ± 4.8 km in thickness. The most abundant elements in the Martian crust are silicon , oxygen , iron , magnesium , aluminium , calcium , and potassium . Mars is confirmed to be seismically active; in 2019 it
3213-512: A northwestern and northeastern branch upon reaching an obstacle. The southwestern lava flow is 6 km long and was fairly viscous when it was erupted. It almost reaches a road southwest of the volcano. The third flow is just east from the southwestern and descends an altitude of 2 km . The flows have levee -like structures and ridges. On the northern flank is Azufrera Esperanto, an 5561 m high eroded volcano with sulfur deposits and traces of hydrothermal alteration. The existence of
3402-429: A north–south line, producing up to 20 km long lava flows and lava domes in their summit regions. The cones and associated lava flows are heavily eroded by glaciation and hydrothermal alteration and buried by more recent volcanic rocks, but still make up about 70% of the surface of the volcano especially in its western sector. The former crater of Llullaillaco forms a plateau at 5600–6100 m elevation. At
3591-443: A paper was published suggesting a new definition for the word 'volcano' that includes processes such as cryovolcanism . It suggested that a volcano be defined as 'an opening on a planet or moon's surface from which magma , as defined for that body, and/or magmatic gas is erupted.' This article mainly covers volcanoes on Earth. See § Volcanoes on other celestial bodies and cryovolcano for more information. The word volcano
3780-473: A record of erosion caused by the catastrophic release of water from subsurface aquifers, though some of these structures have been hypothesized to result from the action of glaciers or lava. One of the larger examples, Ma'adim Vallis , is 700 kilometres (430 mi) long, much greater than the Grand Canyon, with a width of 20 kilometres (12 mi) and a depth of 2 kilometres (1.2 mi) in places. It
3969-588: A remnant of that ring. The geological history of Mars can be split into many periods, but the following are the three primary periods: Geological activity is still taking place on Mars. The Athabasca Valles is home to sheet-like lava flows created about 200 million years ago. Water flows in the grabens called the Cerberus Fossae occurred less than 20 million years ago, indicating equally recent volcanic intrusions. The Mars Reconnaissance Orbiter has captured images of avalanches. Mars
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#17327765831784158-460: A result, the seasons in its southern hemisphere are more extreme and the seasons in its northern are milder than would otherwise be the case. The summer temperatures in the south can be warmer than the equivalent summer temperatures in the north by up to 30 °C (54 °F). Martian surface temperatures vary from lows of about −110 °C (−166 °F) to highs of up to 35 °C (95 °F) in equatorial summer. The wide range in temperatures
4347-482: A road or path from the northwest. Another abandoned mine lies south of the volcano. Mina Amalia is an abandoned borate mine and Mina Luisa and Mina Maria abandoned salt mines at Salar de Llullaillaco. A weather station installed on Llullaillaco in 2004 was for some time the highest in the world. The region is dry and located at high altitudes, making work in the area difficult. The extreme environmental conditions have been compared to conditions on Mars . The volcano
4536-455: A run-up mark on Cerro Rosado. Such ridges may be associated with uneven underlying terrain. The surface of the slide is covered by lava bombs less than 1 m long, blocks exceeding 2 m width, cobbles , and gravel -like rocks. The largest blocks with sizes of up to 20 m are found close to the collapse scarp. Overall, the margins of the landslide are very crisp and the surface covered by hummocks . The landslide deposit covers
4725-421: A seated position. It is not clear how they were killed; most likely, they were suffocated or buried alive but unconscious, and the boy may have been dead before reaching the summit. The younger children bore traces of cranial deformation . The Llullaillaco bodies are among the best preserved known pre-Columbian mummies owing to the cold, dry and oxygen-poor conditions of the summit which prevent microbial decay of
4914-440: A small cone with about four associated lava domes , which reach lengths of 1–3 km and have abrupt walls. Three hollows, probably volcanic craters , lie east of a 200 m long crest at the summit. The slopes of the volcano are fairly steep, with an altitude drop of 1800 m over only 3 km horizontal distance. The slopes high up are steeper than those at lower altitudes. A plateau at 5600–6100 m elevation
5103-471: A small crater (later called Airy-0 ), located in the Sinus Meridiani ("Middle Bay" or "Meridian Bay"), was chosen by Merton E. Davies , Harold Masursky , and Gérard de Vaucouleurs for the definition of 0.0° longitude to coincide with the original selection. Because Mars has no oceans, and hence no " sea level ", a zero-elevation surface had to be selected as a reference level; this is called
5292-535: A storm over a small area, to gigantic storms that cover the entire planet. They tend to occur when Mars is closest to the Sun, and have been shown to increase global temperature. Seasons also produce dry ice covering polar ice caps . Large areas of the polar regions of Mars While Mars contains water in larger amounts , most of it is dust covered water ice at the Martian polar ice caps . The volume of water ice in
5481-482: A surface of about 165 square kilometres (64 sq mi). Its volume has been estimated at 1–2 km and the speed at 45–90 metres per second (150–300 ft/s). This speed range is comparable to that of the Colima , Lastarria , and Mount St. Helens debris avalanches. The landslide occurred no later than 156,000 – 148,000 ± 5,000 years ago, it might coincide with the 48,000 year old lava flow. Another possibility
5670-491: A very thick lithosphere compared to Earth. Below this the mantle gradually becomes more ductile, and the seismic wave velocity starts to grow again. The Martian mantle does not appear to have a thermally insulating layer analogous to Earth's lower mantle ; instead, below 1050 km in depth, it becomes mineralogically similar to Earth's transition zone . At the bottom of the mantle lies a basal liquid silicate layer approximately 150–180 km thick. Mars's iron and nickel core
5859-632: A volcano is largely determined by the composition of the lava it erupts. The viscosity (how fluid the lava is) and the amount of dissolved gas are the most important characteristics of magma, and both are largely determined by the amount of silica in the magma. Magma rich in silica is much more viscous than silica-poor magma, and silica-rich magma also tends to contain more dissolved gases. Lava can be broadly classified into four different compositions: Mafic lava flows show two varieties of surface texture: ʻAʻa (pronounced [ˈʔaʔa] ) and pāhoehoe ( [paːˈho.eˈho.e] ), both Hawaiian words. ʻAʻa
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6048-555: A volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit; however, this describes just one of the many types of volcano. The features of volcanoes are varied. The structure and behaviour of volcanoes depend on several factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have landscape features such as massive plateaus . Vents that issue volcanic material (including lava and ash ) and gases (mainly steam and magmatic gases) can develop anywhere on
6237-465: A volcano that has experienced one or more eruptions that produced over 1,000 cubic kilometres (240 cu mi) of volcanic deposits in a single explosive event. Such eruptions occur when a very large magma chamber full of gas-rich, silicic magma is emptied in a catastrophic caldera -forming eruption. Ash flow tuffs emplaced by such eruptions are the only volcanic product with volumes rivalling those of flood basalts . Supervolcano eruptions, while
6426-452: Is Syrtis Major Planum . The permanent northern polar ice cap is named Planum Boreum . The southern cap is called Planum Australe . Mars's equator is defined by its rotation, but the location of its Prime Meridian was specified, as was Earth's (at Greenwich ), by choice of an arbitrary point; Mädler and Beer selected a line for their first maps of Mars in 1830. After the spacecraft Mariner 9 provided extensive imagery of Mars in 1972,
6615-413: Is vitrophyric or porphyritic . Several dry valleys originate on Llullaillaco, including Quebrada de las Zorritas on the north-northeastern slope, Quebrada El Salado and Quebrada Llullaillaco on the northwestern slope, and Quebrada La Barda on the southwestern slope. Most of the dry valleys drain into Salar de Punta Negra. There is little erosion by water, and the valley network is poorly developed. There
6804-404: Is a salt pan 20 km east of the volcano, behind Cerro Rosado. It lies at 3750 m elevation, and features warm springs at its western and southwestern shores. Due east of Salar de Llullaillaco is Salar de Arizaro . The terrain around Llullaillaco consists of andesite and dacite lavas and pyroclastics of Miocene to Pliocene age. The basement in the 70 km thick crust
6993-739: Is a volcanic field of over 60 cinder cones. Based on satellite images, it has been suggested that cinder cones might occur on other terrestrial bodies in the Solar system too; on the surface of Mars and the Moon. Stratovolcanoes (composite volcanoes) are tall conical mountains composed of lava flows and tephra in alternate layers, the strata that gives rise to the name. They are also known as composite volcanoes because they are created from multiple structures during different kinds of eruptions. Classic examples include Mount Fuji in Japan, Mayon Volcano in
7182-406: Is a light albedo feature clearly visible from Earth. There are other notable impact features, such as Argyre , which is around 1,800 kilometres (1,100 mi) in diameter, and Isidis , which is around 1,500 kilometres (930 mi) in diameter. Due to the smaller mass and size of Mars, the probability of an object colliding with the planet is about half that of Earth. Mars is located closer to
7371-499: Is an example. Volcanoes are usually not created where two tectonic plates slide past one another. Large eruptions can affect atmospheric temperature as ash and droplets of sulfuric acid obscure the Sun and cool Earth's troposphere . Historically, large volcanic eruptions have been followed by volcanic winters which have caused catastrophic famines. Other planets besides Earth have volcanoes. For example, volcanoes are very numerous on Venus. Mars has significant volcanoes. In 2009,
7560-561: Is an imposing mountain, rising by 3800 m and 3750 m above the Salar de Punta Negra 36 km and Sala de Llullaillaco 20 km away, respectively. With a summit height of 6723 m , (or 6739 m ) it is one of the highest mountains in the Andes (third highest in Chile and seventh-highest in the Andes, according to John Biggar) and the second- or third-highest volcano in
7749-432: Is approximately half the diameter of Earth, with a surface area only slightly less than the total area of Earth's dry land. Mars is less dense than Earth, having about 15% of Earth's volume and 11% of Earth's mass , resulting in about 38% of Earth's surface gravity . Mars is the only presently known example of a desert planet , a rocky planet with a surface akin to that of Earth's hot deserts . The red-orange appearance of
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7938-590: Is called volcanism . On Earth, volcanoes are most often found where tectonic plates are diverging or converging , and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge , such as the Mid-Atlantic Ridge , has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there
8127-412: Is characterized by a rough, clinkery surface and is the typical texture of cooler basalt lava flows. Pāhoehoe is characterized by its smooth and often ropey or wrinkly surface and is generally formed from more fluid lava flows. Pāhoehoe flows are sometimes observed to transition to ʻaʻa flows as they move away from the vent, but never the reverse. More silicic lava flows take the form of block lava, where
8316-766: Is completely molten, with no solid inner core. It is around half of Mars's radius, approximately 1650–1675 km, and is enriched in light elements such as sulfur , oxygen, carbon , and hydrogen . Mars is a terrestrial planet with a surface that consists of minerals containing silicon and oxygen, metals , and other elements that typically make up rock . The Martian surface is primarily composed of tholeiitic basalt , although parts are more silica -rich than typical basalt and may be similar to andesitic rocks on Earth, or silica glass. Regions of low albedo suggest concentrations of plagioclase feldspar , with northern low albedo regions displaying higher than normal concentrations of sheet silicates and high-silicon glass. Parts of
8505-512: Is connected to the snowfields. Cryoplanation and solifluction landforms are also observed on Iris and Mitral. The landforms probably developed during past periods where the climate was more humid. Vegetation is scarce in the arid climate, especially below 3700–3800 m altitude where precipitation is too low to permit vegetation development. It takes the form of a steppe , with sparse cushion plants and shrubs . Acantholippia punensis , Atriplex imbricata , and Cristaria andicola are
8694-678: Is derived from the Quechua word llulla meaning "false", "lie" or "deceitful" and yaku or llaco meaning "water". This name probably refers to meltwater from snow, which flows down the slopes but then is absorbed into the soil; normally mountains are sources for water. Another possibility is that it refers to the danger from floods in the local valleys. Other translations are ( Aymara ) "hot water" after lloclla "warm" and yacu "water", and (Quechua) "thinking", "memory"+"water" or "thing that hardens after forming tender" llullu , which may refer to volcanic activity. Llullaillaco
8883-565: Is derived from the name of Vulcano , a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan , the god of fire in Roman mythology . The study of volcanoes is called volcanology , sometimes spelled vulcanology . According to the theory of plate tectonics, Earth's lithosphere , its rigid outer shell, is broken into sixteen larger and several smaller plates. These are in slow motion, due to convection in
9072-429: Is divided into two kinds of areas, with differing albedo. The paler plains covered with dust and sand rich in reddish iron oxides were once thought of as Martian "continents" and given names like Arabia Terra ( land of Arabia ) or Amazonis Planitia ( Amazonian plain ). The dark features were thought to be seas, hence their names Mare Erythraeum , Mare Sirenum and Aurorae Sinus . The largest dark feature seen from Earth
9261-487: Is due to the thin atmosphere which cannot store much solar heat, the low atmospheric pressure (about 1% that of the atmosphere of Earth ), and the low thermal inertia of Martian soil. The planet is 1.52 times as far from the Sun as Earth, resulting in just 43% of the amount of sunlight. Mars has the largest dust storms in the Solar System, reaching speeds of over 160 km/h (100 mph). These can vary from
9450-584: Is expressed using the volcanic explosivity index (VEI), which ranges from 0 for Hawaiian-type eruptions to 8 for supervolcanic eruptions. As of December 2022 , the Smithsonian Institution 's Global Volcanism Program database of volcanic eruptions in the Holocene Epoch (the last 11,700 years) lists 9,901 confirmed eruptions from 859 volcanoes. The database also lists 1,113 uncertain eruptions and 168 discredited eruptions for
9639-621: Is formed by Paleozoic sedimentary and volcanic rocks, including marine and volcanic sediments and intrusive rocks . It is mostly buried by Cenozoic volcanic rocks, except in isolated outcrops both west and east of Llullaillaco: The 282 ± 7 million years old Llullaillaco plutonic complex, the Devonian - Carboniferous Zorritas Formation and Oligocene -Miocene layers in the Quebrada de las Zorritas. The rocks of Llullaillaco overlie both this basement and Tertiary ignimbrites. The terrain around
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#17327765831789828-572: Is intense. The high insolation is due to the lack of cloud cover , the high altitude, and the close coincidence between summer solstice with the day where Earth is closest to the Sun . Mean annual precipitation reaches 20–50 millimetres (0.79–1.97 in), decreasing from west to east, and is episodic to the point that it is difficult to give average values. It is most often associated with either convective activity during summer or cyclones during winter. Snowfall can occur down to altitudes of 4000 m . The Andean Dry Diagonal , where half of
10017-612: Is located in the northwestern Argentine Andes, towards the southern end of the Puna. The frontier between Argentina and Chile passes over the mountain. The Argentine portion is in the Los Andes Department of Salta Province and the Chilean in Chile's Antofagasta Region . About 30 km northeast of Llullaillaco, a railway crosses the Andes at Socompa . Humans first moved into the area about 8,000 BCE . The region
10206-547: Is named after the volcano. There seems to be a population of the Punta de Vacas leaf-eared mouse on Llullaillaco; it likely is the highest-elevation permanent population of any known vertebrate species. Lichens grow on rocks. Algae including snow algae and cyanobacteria live on the penitentes, sometimes forming coloured patches, and algae and microbial mats grow in Lago Llullaillaco. A species of bacterium
10395-403: Is not usually known what triggers the collapse, although eruption-associated earthquakes are suspected to play a role. Other volcanoes in the region with sector collapses are: Lastarria, Ollague , San Pedro , Socompa, and Tata Sabaya . The Mellado and Cerro Rosado volcanoes close to Llullaillaco also display evidence of sector collapses. Volcanism in the Andes is caused by the subduction of
10584-482: Is of early Pleistocene age, but the time of the transition between Llullaillaco I and Llullaillaco II is unclear: Either it took place 450,000 years ago, or less than 41,000 ± 1,000 years ago. Ages of 5,600 ± 250 years have been obtained for Llullaillaco II rocks recovered at an altitude of over 6000 m . The young-looking lava flows were at first thought to be of Holocene age, but dating methods yielded ages of less than one million years ( potassium-argon dating ) for
10773-725: Is one of more than 1,000 volcanoes in the CVZ. At least 44 volcanic centres with historical activity and 18 large caldera-forming volcanoes have been identified in the Central Volcanic Zone; the most active is Lascar , and Guallatiri and San Pedro have had historical eruptions as well. Volcanism in the Central Volcanic Zone mostly occurs on the Altiplano and the Cordillera Occidental , where high stratovolcanoes with heights of over 6000 m occur. One of
10962-537: Is one of the several tuyas in the area of the Tuya River and Tuya Range in northern British Columbia. Tuya Butte was the first such landform analysed and so its name has entered the geological literature for this kind of volcanic formation. The Tuya Mountains Provincial Park was recently established to protect this unusual landscape, which lies north of Tuya Lake and south of the Jennings River near
11151-732: Is stretching and thinning of the crust's plates, such as in the East African Rift , the Wells Gray-Clearwater volcanic field , and the Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary , 3,000 kilometres (1,900 mi) deep within Earth. This results in hotspot volcanism , of which the Hawaiian hotspot
11340-519: Is striking: northern plains flattened by lava flows contrast with the southern highlands, pitted and cratered by ancient impacts. It is possible that, four billion years ago, the Northern Hemisphere of Mars was struck by an object one-tenth to two-thirds the size of Earth's Moon . If this is the case, the Northern Hemisphere of Mars would be the site of an impact crater 10,600 by 8,500 kilometres (6,600 by 5,300 mi) in size, or roughly
11529-411: Is that the collapse took place in multiple failures. Some volcanic rocks were still hot at the time of the collapse, indicating that volcanic activity occurred immediately before the collapse. A smaller undated avalanche occurred on the northeastern flank. Such landslides are common at volcanoes, where they are favoured by the steep edifices that form from lava flows being stacked on top of each other. It
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#173277658317811718-584: Is the remnant of an eroded crater from an early stage in Llullaillaco's development. Three young-looking, 4.5–8 km long lava flows emanate from the summit cone to the north and south. Morphologically, these flows are reddish-black aa lava flows and feature black and reddish glassy blocks with sizes of 5 m . The fronts of the stubby, lobe-shaped flows are up to 15 m thick. Morphologically, these flows are reddish-black aa lava flows and feature blocks with sizes of 5 m . The northern flow has prominent levee -like structures and splits into
11907-657: Is thought to have been carved by flowing water early in Mars's history. The youngest of these channels is thought to have formed only a few million years ago. Elsewhere, particularly on the oldest areas of the Martian surface, finer-scale, dendritic networks of valleys are spread across significant proportions of the landscape. Features of these valleys and their distribution strongly imply that they were carved by runoff resulting from precipitation in early Mars history. Subsurface water flow and groundwater sapping may play important subsidiary roles in some networks, but precipitation
12096-471: Is typically low in silica, shield volcanoes are more common in oceanic than continental settings. The Hawaiian volcanic chain is a series of shield cones, and they are common in Iceland , as well. Lava domes are built by slow eruptions of highly viscous lava. They are sometimes formed within the crater of a previous volcanic eruption, as in the case of Mount St. Helens , but can also form independently, as in
12285-528: Is water only episodically, during snowmelt . Only Quebrada de las Zorritas carries permanent water. There is a permanent spring there, possibly in Quebrada de Llullaillaco and Quebrada de Tocomar as well, while there are no known springs on the Argentine side of Llullaillaco. Darapsky in 1900 reported the existence of warm springs at Ojo del Llullaillaco and Ojo de Zorritas Several small lakes are found at 5850 m elevation. At 6170 m elevation on
12474-453: The Viking 1 probe in 1976. As of 2023, there are at least 11 active probes orbiting Mars or on the Martian surface. Mars is an attractive target for future human exploration missions , though in the 2020s no such mission is planned. Scientists have theorized that during the Solar System's formation , Mars was created as the result of a random process of run-away accretion of material from
12663-550: The areoid of Mars, analogous to the terrestrial geoid . Zero altitude was defined by the height at which there is 610.5 Pa (6.105 mbar ) of atmospheric pressure. This pressure corresponds to the triple point of water, and it is about 0.6% of the sea level surface pressure on Earth (0.006 atm). For mapping purposes, the United States Geological Survey divides the surface of Mars into thirty cartographic quadrangles , each named for
12852-425: The 5561 m high Azufrera Esperanto mountain 5 km north of Llullaillaco little original volcanic substance is preserved and where erosion has exposed deeply altered white rock. Llullaillaco II on the southern and northeastern flank is better preserved; the toes of the lava flows reach thicknesses of 500 m . Its lava flows are less extensive than the ones of Llullaillaco I. Pyroclastic flow deposits with
13041-617: The Cascade Volcanoes or the Japanese Archipelago , or the eastern islands of Indonesia . Hotspots are volcanic areas thought to be formed by mantle plumes , which are hypothesized to be columns of hot material rising from the core-mantle boundary. As with mid-ocean ridges, the rising mantle rock experiences decompression melting which generates large volumes of magma. Because tectonic plates move across mantle plumes, each volcano becomes inactive as it drifts off
13230-503: The Galán caldera; it influenced the development of Llullaillaco. Other faults are the northeast-southwest trending Guanaqueros and the northwest-southeast trending Imilac-Salina del Fraile; Llullaillaco formed on the trace of the latter fault. Llullaillaco has produced dacites , which define a potassium- and aluminum-rich calc-alkaline suite. Some rocks display shoshonitic characteristics typical for lavas erupted at large distance from
13419-453: The Martian hemispheric dichotomy , created the smooth Borealis basin that covers 40% of the planet. A 2023 study shows evidence, based on the orbital inclination of Deimos (a small moon of Mars), that Mars may once have had a ring system 3.5 billion years to 4 billion years ago. This ring system may have been formed from a moon, 20 times more massive than Phobos , orbiting Mars billions of years ago; and Phobos would be
13608-741: The Nazca Plate and the Antarctic Plate beneath the South America Plate . The Nazca Plate subducts at a speed of 7–9 centimetres per year (2.8–3.5 in/year) and the Antarctic Plate at a speed of 2 cm/year . Volcanism is not continuous along the Andes, rather it occurs in four distinct volcanic zones: Northern Volcanic Zone (NVZ), Central Volcanic Zone (CVZ), Southern Volcanic Zone (SVZ) and Austral Volcanic Zone (AVZ). The formation of magma results from
13797-471: The Noachian period (4.5 to 3.5 billion years ago), Mars's surface was marked by meteor impacts , valley formation, erosion, and the possible presence of water oceans . The Hesperian period (3.5 to 3.3–2.9 billion years ago) was dominated by widespread volcanic activity and flooding that carved immense outflow channels . The Amazonian period, which continues to the present, has been marked by
13986-509: The Pleistocene in two stages, named Llullaillaco I and Llullaillaco II. The oldest rocks are about 1.5 million years old. About 150,000 years ago, the volcano's southeastern flank collapsed, generating a debris avalanche that reached as far as 25 km from the summit. During the last stage, three conspicuous lava flows were emplaced on the summit. The youngest dated rocks are 930 ± 140 years old, but there are reports of activity from
14175-478: The Pliocene - Quaternary . Mitral mountain ( 5015 m ) lies southwest of Llullaillaco and is of Miocene age. It features an eroded crater that opens to the northwest. Iris mountain ( 5461 m ) north of Llullaillaco is constructed of Pliocene rocks. Other volcanoes in the neighbourhood are Dos Naciones, Cerro Silla, and Cerro 5074. Llullaillaco is associated with a local crustal upwarp. Salar de Llullaillaco
14364-656: The Yellowknife Bay area in the Glenelg terrain. In September 2015, NASA announced that they had found strong evidence of hydrated brine flows in recurring slope lineae , based on spectrometer readings of the darkened areas of slopes. These streaks flow downhill in Martian summer, when the temperature is above −23 °C, and freeze at lower temperatures. These observations supported earlier hypotheses, based on timing of formation and their rate of growth, that these dark streaks resulted from water flowing just below
14553-415: The asteroid belt , so it has an increased chance of being struck by materials from that source. Mars is more likely to be struck by short-period comets , i.e. , those that lie within the orbit of Jupiter . Martian craters can have a morphology that suggests the ground became wet after the meteor impact. The large canyon, Valles Marineris (Latin for " Mariner Valleys", also known as Agathodaemon in
14742-834: The landform and may give rise to smaller cones such as Puʻu ʻŌʻō on a flank of Kīlauea in Hawaii. Volcanic craters are not always at the top of a mountain or hill and may be filled with lakes such as with Lake Taupō in New Zealand. Some volcanoes can be low-relief landform features, with the potential to be hard to recognize as such and be obscured by geological processes. Other types of volcano include cryovolcanoes (or ice volcanoes), particularly on some moons of Jupiter , Saturn , and Neptune ; and mud volcanoes , which are structures often not associated with known magmatic activity. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes except when
14931-418: The late glacial , a wet period gave rise to lakes in the Altiplano ( Lake Tauca pluvial). Water discharge from Llullaillaco and neighbouring mountains into Salar de Punta Negra increased, leading to the formation of standing water bodies. As glaciers retreated between 15,000 and 10,000 years ago, lakes shrank. Climate was extremely dry between 9,000 and 4,000 years ago and temperatures warmer than today during
15120-401: The protoplanetary disk that orbited the Sun. Mars has many distinctive chemical features caused by its position in the Solar System. Elements with comparatively low boiling points, such as chlorine , phosphorus , and sulfur , are much more common on Mars than on Earth; these elements were probably pushed outward by the young Sun's energetic solar wind . After the formation of the planets,
15309-434: The second- or third-highest volcano in the world . Despite its height, it is not clear whether the volcano has any glaciers or merely patches of perennial snow and ice. Between 3700 m and 5000 m elevation there is a sparse plant cover, while at lower altitudes the climate is too dry for plants to grow. A species of mouse on Llullaillaco is the highest-living known vertebrate species. The volcano formed during
15498-468: The volcanic arc to broaden to about 250 km . 25 million years ago, the "Quechua event" triggered the uplift of the Puna-Altiplano, a highland covering a surface area of 500 000 km and reaching an altitude of 3700 m . In the late Miocene-Pliocene a phase of strong ignimbrite volcanism occurred. About 2 million years ago, the "Diaguita deformation" was characterized by a change in
15687-505: The wind as a dominant influence on geological processes . Due to Mars's geological history, the possibility of past or present life on Mars remains of great scientific interest. Since the late 20th century, Mars has been explored by uncrewed spacecraft and rovers , with the first flyby by the Mariner 4 probe in 1965, the first orbit by the Mars 2 probe in 1971, and the first landing by
15876-495: The 19th century. The mountain's first recorded climb was in 1950, but traces of earlier climbs and a number of archaeological sites were found on the mountain and at its feet; Llullaillaco marks the highest archaeological site in the world. In 1999, the mummified remains of three children, known as the Children of Llullaillaco , were found at its summit. They are presumed to have been human sacrifices . The name Llullaillaco
16065-472: The Andes, with forty mountains featuring sites in Salta Province alone. Because of the findings, the summit area of the volcano in 2001 was classified as a Lugar Histórico Nacional by the government of Argentina, and in 24 June 2014 the entire Llullaillaco complex was declared a World Heritage Site by UNESCO . A number of myths are associated with Llullaillaco, and the mountain is still important to
16254-478: The Martian ionosphere , lowering the atmospheric density by stripping away atoms from the outer layer. Both Mars Global Surveyor and Mars Express have detected ionized atmospheric particles trailing off into space behind Mars, and this atmospheric loss is being studied by the MAVEN orbiter. Compared to Earth, the atmosphere of Mars is quite rarefied. Atmospheric pressure on the surface today ranges from
16443-538: The Martian sky a tawny color when seen from the surface. It may take on a pink hue due to iron oxide particles suspended in it. The concentration of methane in the Martian atmosphere fluctuates from about 0.24 ppb during the northern winter to about 0.65 ppb during the summer. Estimates of its lifetime range from 0.6 to 4 years, so its presence indicates that an active source of the gas must be present. Methane could be produced by non-biological process such as serpentinization involving water, carbon dioxide, and
16632-415: The Martian surface is caused by ferric oxide , or rust . It can look like butterscotch ; other common surface colors include golden, brown, tan, and greenish, depending on the minerals present. Like Earth, Mars is differentiated into a dense metallic core overlaid by less dense rocky layers. The outermost layer is the crust, which is on average about 42–56 kilometres (26–35 mi) thick, with
16821-542: The Moon, Johann Heinrich von Mädler and Wilhelm Beer were the first areographers. They began by establishing that most of Mars's surface features were permanent and by more precisely determining the planet's rotation period. In 1840, Mädler combined ten years of observations and drew the first map of Mars. Features on Mars are named from a variety of sources. Albedo features are named for classical mythology. Craters larger than roughly 50 km are named for deceased scientists and writers and others who have contributed to
17010-400: The Northern Hemisphere of Mars, spanning 10,600 by 8,500 kilometres (6,600 by 5,300 mi), or roughly four times the size of the Moon's South Pole–Aitken basin , which would be the largest impact basin yet discovered if confirmed. It has been hypothesized that the basin was formed when Mars was struck by a Pluto -sized body about four billion years ago. The event, thought to be the cause of
17199-486: The Olacapato-El Toro and Archibarca lineaments, which control where volcanoes and geothermal systems form. They extend diagonally across the volcanic arc and are accompanied by volcanic manifestations at substantial distances from the arc. The Archibarca lineament runs from the Escondida copper deposit, over Llullaillaco (where it crosses the volcanic arc ), Corrida de Cori , Archibarca , Antofalla to
17388-622: The Philippines, and Mount Vesuvius and Stromboli in Italy. Ash produced by the explosive eruption of stratovolcanoes has historically posed the greatest volcanic hazard to civilizations. The lavas of stratovolcanoes are higher in silica, and therefore much more viscous, than lavas from shield volcanoes. High-silica lavas also tend to contain more dissolved gas. The combination is deadly, promoting explosive eruptions that produce great quantities of ash, as well as pyroclastic surges like
17577-591: The Salar de Punta Negra. The occurrence of past glaciation at Llullaillaco and its neighbours during the Pleistocene is also uncertain. Some traces of past glacier activity are found in the summit area, cirques may have existed on the northwestern slope, where glaciers may have descended to 5100 m elevation, and a moraine girdle may have formed at 4900 m elevation. There is evidence of glacial landforms destroyed by lava and volcanic mudflows . It
17766-489: The Salina de Llullaillaco 25 km east of the summit, extending up to 5 km into the salar. The toe of the avalanche reaches a thickness of 10 m above the salar in the avalanche's southern lobe. Part of the avalanche was channelled in a valley between Cerro Rosado and an unnamed volcano farther south. When it reached Cerro Rosado, the avalanche climbed about 400 m and mostly continued to flow southeast into
17955-613: The USGS defines a volcano as active whenever subterranean indicators, such as earthquake swarms , ground inflation, or unusually high levels of carbon dioxide or sulfur dioxide are present. The USGS defines a dormant volcano as any volcano that is not showing any signs of unrest such as earthquake swarms, ground swelling, or excessive noxious gas emissions, but which shows signs that it could yet become active again. Many dormant volcanoes have not erupted for thousands of years, but have still shown signs that they may be likely to erupt again in
18144-462: The area of Europe, Asia, and Australia combined, surpassing Utopia Planitia and the Moon's South Pole–Aitken basin as the largest impact crater in the Solar System. Mars is scarred by a number of impact craters: a total of 43,000 observed craters with a diameter of 5 kilometres (3.1 mi) or greater have been found. The largest exposed crater is Hellas , which is 2,300 kilometres (1,400 mi) wide and 7,000 metres (23,000 ft) deep, and
18333-419: The atmosphere is about 10.8 kilometres (6.7 mi), which is higher than Earth's 6 kilometres (3.7 mi), because the surface gravity of Mars is only about 38% of Earth's. The atmosphere of Mars consists of about 96% carbon dioxide , 1.93% argon and 1.89% nitrogen along with traces of oxygen and water. The atmosphere is quite dusty, containing particulates about 1.5 μm in diameter which give
18522-406: The atmosphere is small, but enough to produce larger clouds of water ice and different cases of snow and frost , often mixed with snow of carbon dioxide dry ice . Landforms visible on Mars strongly suggest that liquid water has existed on the planet's surface. Huge linear swathes of scoured ground, known as outflow channels , cut across the surface in about 25 places. These are thought to be
18711-499: The bodies - except for the youngest mummy, which had been damaged by lightning . They were ostensibly human sacrifices offered to the gods of the Incan pantheon on mountaintops. Inca human sacrifices were initiated for various reasons, either to mark particular events such as the death of an Inca emperor , to appease nature during natural disasters or to secure resources from the mountain gods. The chosen sacrifices were children, as
18900-510: The boundary with the Yukon Territory . Mud volcanoes (mud domes) are formations created by geo-excreted liquids and gases, although several processes may cause such activity. The largest structures are 10 kilometres in diameter and reach 700 meters high. The material that is expelled in a volcanic eruption can be classified into three types: The concentrations of different volcanic gases can vary considerably from one volcano to
19089-467: The broken fragments of "Tintina" rock and "Sutton Inlier" rock as well as in veins and nodules in other rocks like "Knorr" rock and "Wernicke" rock . Analysis using the rover's DAN instrument provided evidence of subsurface water, amounting to as much as 4% water content, down to a depth of 60 centimetres (24 in), during the rover's traverse from the Bradbury Landing site to
19278-402: The case of Lassen Peak . Like stratovolcanoes, they can produce violent, explosive eruptions, but the lava generally does not flow far from the originating vent. Cryptodomes are formed when viscous lava is forced upward causing the surface to bulge. The 1980 eruption of Mount St. Helens was an example; lava beneath the surface of the mountain created an upward bulge, which later collapsed down
19467-415: The cratered terrain in southern highlands – this terrain observation is known as the Martian dichotomy . Mars hosts many enormous extinct volcanoes (the tallest is Olympus Mons , 21.9 km or 13.6 mi tall) and one of the largest canyons in the Solar System ( Valles Marineris , 4,000 km or 2,500 mi long). Geologically , the planet is fairly active with marsquakes trembling underneath
19656-457: The deformation regimen from crustal shortening to strike-slip faulting and of volcanism from voluminous felsic eruptions to isolated stratovolcanoes and back-arc mafic volcanism. A slowdown in the subduction may have caused this change. Nowadays most volcanism occurs at the western edge of the Puna, where volcanoes such as Lascar and Llullaillaco formed. Volcanism in the Central Volcanic Zone may be affected by deep-seated lineaments, such as
19845-502: The early Holocene ( Holocene Climatic Optimum ). Deposits in Quebrada de las Zorritas valley indicate that between 2,500 and 1,600 radiocarbon years ago runoff was more intense. It is not clear whether there are glaciers on Llullaillaco - some sources contend that there are no glaciers on Llullaillaco, which would make it the highest mountain in the world without one, while others state that there are small glaciers above 6000 m altitude, four permanent snowpatches of glaciers on
20034-458: The edges of boulders and other obstacles in their path. The commonly accepted hypotheses include that they are dark underlying layers of soil revealed after avalanches of bright dust or dust devils . Several other explanations have been put forward, including those that involve water or even the growth of organisms. Environmental radiation levels on the surface are on average 0.64 millisieverts of radiation per day, and significantly less than
20223-799: The enormous area they cover, and subsequent concealment under vegetation and glacial deposits, supervolcanoes can be difficult to identify in the geologic record without careful geologic mapping . Known examples include Yellowstone Caldera in Yellowstone National Park and Valles Caldera in New Mexico (both western United States); Lake Taupō in New Zealand; Lake Toba in Sumatra , Indonesia; and Ngorongoro Crater in Tanzania. Volcanoes that, though large, are not large enough to be called supervolcanoes, may also form calderas in
20412-402: The first plants that grow above this elevation. They are joined at 3900 m altitude by Stipa frigida which can be found up to 4910 m of altitude. The maximum vegetation density is found around 4250 m with 12% of the surface. At this altitude, Adesmia spinosissima , Fabiana bryoides , Mulinum crassifolium , and Parastrephia quadrangularis are found in addition to
20601-429: The flanks of the volcano Arsia Mons . The caves, named after loved ones of their discoverers, are collectively known as the "seven sisters". Cave entrances measure from 100 to 252 metres (328 to 827 ft) wide and they are estimated to be at least 73 to 96 metres (240 to 315 ft) deep. Because light does not reach the floor of most of the caves, they may extend much deeper than these lower estimates and widen below
20790-431: The flow is covered with angular, vesicle-poor blocks. Rhyolitic flows typically consist largely of obsidian . Tephra is made when magma inside the volcano is blown apart by the rapid expansion of hot volcanic gases. Magma commonly explodes as the gas dissolved in it comes out of solution as the pressure decreases when it flows to the surface . These violent explosions produce particles of material that can then fly from
20979-610: The formation of a submarine volcano off the coast of Mayotte . Subglacial volcanoes develop underneath ice caps . They are made up of lava plateaus capping extensive pillow lavas and palagonite . These volcanoes are also called table mountains, tuyas , or (in Iceland) mobergs. Very good examples of this type of volcano can be seen in Iceland and in British Columbia . The origin of the term comes from Tuya Butte , which
21168-585: The future. In an article justifying the re-classification of Alaska's Mount Edgecumbe volcano from "dormant" to "active", volcanologists at the Alaska Volcano Observatory pointed out that the term "dormant" in reference to volcanoes has been deprecated over the past few decades and that "[t]he term "dormant volcano" is so little used and undefined in modern volcanology that the Encyclopedia of Volcanoes (2000) does not contain it in
21357-685: The gap between the SVZ and AVZ is associated with the Chile Triple Junction . Minor ridges are associated with decreased volcanism rather than its cessation; the Taltal Ridge projects under Llullaillaco, an area where magma output was less than to the north and south. About 178 volcanoes are found in the Andes , 60 of which have been active in historical times. In addition, there are large calderas and monogenetic volcanoes. Llullaillaco
21546-466: The glossaries or index", however the USGS still widely employs the term. Previously a volcano was often considered to be extinct if there were no written records of its activity. Such a generalization is inconsistent with observation and deeper study, as has occurred recently with the unexpected eruption of the Chaitén volcano in 2008. Modern volcanic activity monitoring techniques, and improvements in
21735-830: The gods were thought to prefer pure offerings, preferably children with unblemished bodies and virgin girls. According to historical sources and analyses of the mummies, the children came from families with high social standing and were well nourished. They were brought to mountains thousands of kilometres away and killed at the top. Other archaeological objects found along with the mummies included: Bags made out of leather , headdresses with feathers , pottery (cooking instruments like jars, plates, pots and vases), statues representing both people (male and female) and animals made out of gold , silver or Spondylus ( oyster ) shells, shoes and textiles , wooden and woolen vessels. The vessels and bags contained coca leaves, hairs and human nails . A total of 145 objects were found together with
21924-456: The ground, dust devils sweeping across the landscape, and cirrus clouds . Carbon dioxide is substantially present in Mars's polar ice caps and thin atmosphere . During a year, there are large surface temperature swings on the surface between −78.5 °C (−109.3 °F) to 5.7 °C (42.3 °F) similar to Earth's seasons , as both planets have significant axial tilt . Mars was formed approximately 4.5 billion years ago. During
22113-573: The inhabitants of Socaire east of the Salar de Atacama , from where it is visible. Some ascents are done for ritual reasons. In March 1999, excavations of the platform by a team of archaeologists led by Johan Reinhard, found three mummies of children buried at 1.7 m depth in partially natural, partially excavated pits. They were a 7-year-old boy, a 6-year-old girl and a 15-year-old girl (later research has suggested lower ages for all three), which are known as "El Niño", "La Niña del Rayo" and "La Doncella" respectively. They were found clothed and in
22302-488: The inner Solar System may have been subjected to the so-called Late Heavy Bombardment . About 60% of the surface of Mars shows a record of impacts from that era, whereas much of the remaining surface is probably underlain by immense impact basins caused by those events. However, more recent modeling has disputed the existence of the Late Heavy Bombardment. There is evidence of an enormous impact basin in
22491-492: The interior of a continent and lead to rifting. Early stages of rifting are characterized by flood basalts and may progress to the point where a tectonic plate is completely split. A divergent plate boundary then develops between the two halves of the split plate. However, rifting often fails to completely split the continental lithosphere (such as in an aulacogen ), and failed rifts are characterized by volcanoes that erupt unusual alkali lava or carbonatites . Examples include
22680-436: The lander showed that the Martian soil has a basic pH of 7.7, and contains 0.6% perchlorate by weight, concentrations that are toxic to humans . Streaks are common across Mars and new ones appear frequently on steep slopes of craters, troughs, and valleys. The streaks are dark at first and get lighter with age. The streaks can start in a tiny area, then spread out for hundreds of metres. They have been seen to follow
22869-471: The largest vertical drops on Eart, almost 15 km , exists between the summit of Llullaillaco and the Peru-Chile Trench 300 km farther west. The Wadati-Benioff zone lies at 180 km depth. The region is dominated by large volcanic cones (often more than 6000 m high) in the Altiplano and Western Cordillera , and extensive salt flats in low-altitude areas. Southeast of
23058-503: The main avalanche path, with only a small flow continuing northeastwards. Part of the run-up avalanche later collapsed backwards over the main avalanche deposit. Unlike Socompa farther north, a landslide scar is only poorly developed at Llullaillaco despite the large size of the collapse; it was largely filled in later by lava flows and volcaniclastic debris. This landslide has been subdivided into four facies and features landforms like levees up to 50 m high, longitudinal ridges and
23247-419: The mid-oceanic ridge is above sea level, volcanic islands are formed, such as Iceland . Subduction zones are places where two plates, usually an oceanic plate and a continental plate, collide. The oceanic plate subducts (dives beneath the continental plate), forming a deep ocean trench just offshore. In a process called flux melting , water released from the subducting plate lowers the melting temperature of
23436-474: The mineral jarosite . This forms only in the presence of acidic water, showing that water once existed on Mars. The Spirit rover found concentrated deposits of silica in 2007 that indicated wet conditions in the past, and in December 2011, the mineral gypsum , which also forms in the presence of water, was found on the surface by NASA's Mars rover Opportunity. It is estimated that the amount of water in
23625-613: The mineral olivine , which is known to be common on Mars, or by Martian life. Compared to Earth, its higher concentration of atmospheric CO 2 and lower surface pressure may be why sound is attenuated more on Mars, where natural sources are rare apart from the wind. Using acoustic recordings collected by the Perseverance rover, researchers concluded that the speed of sound there is approximately 240 m/s for frequencies below 240 Hz, and 250 m/s for those above. Auroras have been detected on Mars. Because Mars lacks
23814-551: The modelling of the factors that produce eruptions, have helped the understanding of why volcanoes may remain dormant for a long time, and then become unexpectedly active again. The potential for eruptions, and their style, depend mainly upon the state of the magma storage system under the volcano, the eruption trigger mechanism and its timescale. For example, the Yellowstone volcano has a repose/recharge period of around 700,000 years, and Toba of around 380,000 years. Vesuvius
24003-415: The most dangerous type, are very rare; four are known from the last million years , and about 60 historical VEI 8 eruptions have been identified in the geologic record over millions of years. A supervolcano can produce devastation on a continental scale, and severely cool global temperatures for many years after the eruption due to the huge volumes of sulfur and ash released into the atmosphere. Because of
24192-510: The most extreme on the planet, with aridity, strong UV radiation , daily freeze-thaw cycles and a lack of nutrients. Life may depend on unusual food sources like gaseous carbon monoxide or organic material (e.g remains of plants) transported to the mountain by winds, while photosynthetic organisms are limited to sites with higher water availability. The area of Llullaillaco is part of the Llullaillaco National Park ,
24381-461: The mountain extends from Licancabur north over the Nevados de Cachi mountains east to Ojos del Salado 250 km south; mountains in between are visible as well. Llullaillaco is a composite volcano formed mostly by lava flows . It rises about 2.2 km - 2.5 km above the surrounding terrain and hundreds of metres above surrounding mountains. The summit of Llullaillaco is formed by
24570-496: The mountain is Salina de Llullaillaco/ Salar de Llullaillaco in Argentina, and Salar de Punta Negra northwest of Llullaillaco in Chile. Neighbouring mountains are 4923 m high Cerro Mitral southwest and 5473 m high Volcan Chuculay north of Llullaillaco. Cerro Rosado is 17 km east of Llullaillaco; iit is a 5383 m high volcano which erupted dacitic lava flows on its northeastern and southern flanks during
24759-712: The mountain is partially covered by alluvial sediments, debris and pumice . Volcanism in the Central Andes began during the Jurassic . A pause in volcanism occurred between 38 and 27 million years ago; about 26 million years ago, the Farallon Plate broke up into the Cocos and Nazca Plates , volcanism resumed in the Central Andes and increased subduction of the Nazca Plate during the late Oligocene caused
24948-427: The mountain is so large, with complex structure at its edges, giving a definite height to it is difficult. Its local relief, from the foot of the cliffs which form its northwest margin to its peak, is over 21 km (13 mi), a little over twice the height of Mauna Kea as measured from its base on the ocean floor. The total elevation change from the plains of Amazonis Planitia , over 1,000 km (620 mi) to
25137-431: The movement of dry dust. No partially degraded gullies have formed by weathering and no superimposed impact craters have been observed, indicating that these are young features, possibly still active. Other geological features, such as deltas and alluvial fans preserved in craters, are further evidence for warmer, wetter conditions at an interval or intervals in earlier Mars history. Such conditions necessarily require
25326-438: The mud volcano is actually a vent of an igneous volcano. Volcanic fissure vents are flat, linear fractures through which lava emerges. Shield volcanoes, so named for their broad, shield-like profiles, are formed by the eruption of low-viscosity lava that can flow a great distance from a vent. They generally do not explode catastrophically but are characterized by relatively gentle effusive eruptions . Since low-viscosity magma
25515-415: The mummies on the summit and these in the cemetery - have been subject to various scientific analyses. The placement of the mummies in museums led to lengthy disputes with organizations advocating the rights of indigenous people. At least two stages of construction are recognized, Llullaillaco I and Llullaillaco II. The first stage originated from two centres (Llullaillaco and Azufrera Esperanto) developed in
25704-661: The mummies. Their discovery drew interest among specialists and the public, and has been cited as a cause for increased tourism to the mountain and increased attention dedicated to native people issues in the region. In 2003 the mummies were at the Catholic University of Salta , before being transferred to the Museum of High Altitude Archaeology of Argentina in 2007, which had been built explicitly to host these mummies. They are kept under special storage conditions to prevent damage. The bodies found at Llullaillaco - both
25893-452: The next. Water vapour is typically the most abundant volcanic gas, followed by carbon dioxide and sulfur dioxide . Other principal volcanic gases include hydrogen sulfide , hydrogen chloride , and hydrogen fluoride . A large number of minor and trace gases are also found in volcanic emissions, for example hydrogen , carbon monoxide , halocarbons , organic compounds, and volatile metal chlorides. The form and style of an eruption of
26082-876: The north side of the mountain. Cinder cones result from eruptions of mostly small pieces of scoria and pyroclastics (both resemble cinders, hence the name of this volcano type) that build up around the vent. These can be relatively short-lived eruptions that produce a cone-shaped hill perhaps 30 to 400 metres (100 to 1,300 ft) high. Most cinder cones erupt only once and some may be found in monogenetic volcanic fields that may include other features that form when magma comes into contact with water such as maar explosion craters and tuff rings . Cinder cones may form as flank vents on larger volcanoes, or occur on their own. Parícutin in Mexico and Sunset Crater in Arizona are examples of cinder cones. In New Mexico , Caja del Rio
26271-479: The northeastern and southern flanks, or a single 0.55 km (as of 2002) glacier above 6500 m elevation. In 2006 the General Water Directorate of Chile stated that there were seven separate ice bodies on the mountain, all on the northwestern side. An ice slab was reported in 1958 on the western slope between 5600–6500 m elevation, but it is not a glacier. The lack of glaciers is
26460-420: The northern flow, 48,000 ± 12,000 years ( argon-argon dating ) on the southwestern flow and 930 ± 140 years ( surface exposure dating ) on an unidentified young flow. Volcano#Dormant A volcano is a rupture in the crust of a planetary-mass object , such as Earth , that allows hot lava , volcanic ash , and gases to escape from a magma chamber below the surface. The process that forms volcanoes
26649-514: The northwest, to the summit approaches 26 km (16 mi), roughly three times the height of Mount Everest , which in comparison stands at just over 8.8 kilometres (5.5 mi). Consequently, Olympus Mons is either the tallest or second-tallest mountain in the Solar System ; the only known mountain which might be taller is the Rheasilvia peak on the asteroid Vesta , at 20–25 km (12–16 mi). The dichotomy of Martian topography
26838-447: The northwestern flank is Lago Llullaillaco lake, a 1.2–1.4 hectares (3.0–3.5 acres) frozen waterbody. It is one of the highest lakes in the world. A major landslide occurred in the volcano's history during the late Pleistocene, probably triggered by volcanic activity. This landslide descended the eastern-southeastern flanks of the volcano into Argentina, first over a steep slope of 20° on the volcano, split around Cerro Rosado and entered
27027-549: The ocean surface as new islands or floating pumice rafts . In May and June 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world. They took the form of unusual humming sounds, and some of the signals detected in November of that year had a duration of up to 20 minutes. An oceanographic research campaign in May 2019 showed that the previously mysterious humming noises were caused by
27216-420: The ocean surface, due to the rapid cooling effect and increased buoyancy in water (as compared to air), which often causes volcanic vents to form steep pillars on the ocean floor. Hydrothermal vents are common near these volcanoes, and some support peculiar ecosystems based on chemotrophs feeding on dissolved minerals. Over time, the formations created by submarine volcanoes may become so large that they break
27405-471: The ocean's surface. In the deep ocean basins, the tremendous weight of the water prevents the explosive release of steam and gases; however, submarine eruptions can be detected by hydrophones and by the discoloration of water because of volcanic gases . Pillow lava is a common eruptive product of submarine volcanoes and is characterized by thick sequences of discontinuous pillow-shaped masses which form underwater. Even large submarine eruptions may not disturb
27594-468: The old canal maps ), has a length of 4,000 kilometres (2,500 mi) and a depth of up to 7 kilometres (4.3 mi). The length of Valles Marineris is equivalent to the length of Europe and extends across one-fifth the circumference of Mars. By comparison, the Grand Canyon on Earth is only 446 kilometres (277 mi) long and nearly 2 kilometres (1.2 mi) deep. Valles Marineris was formed due to
27783-468: The one that destroyed the city of Saint-Pierre in Martinique in 1902. They are also steeper than shield volcanoes, with slopes of 30–35° compared to slopes of generally 5–10°, and their loose tephra are material for dangerous lahars . Large pieces of tephra are called volcanic bombs . Big bombs can measure more than 1.2 metres (4 ft) across and weigh several tons. A supervolcano is defined as
27972-425: The overlying mantle wedge, thus creating magma . This magma tends to be extremely viscous because of its high silica content, so it often does not reach the surface but cools and solidifies at depth . When it does reach the surface, however, a volcano is formed. Thus subduction zones are bordered by chains of volcanoes called volcanic arcs . Typical examples are the volcanoes in the Pacific Ring of Fire , such as
28161-842: The past. This paleomagnetism of magnetically susceptible minerals is similar to the alternating bands found on Earth's ocean floors . One hypothesis, published in 1999 and re-examined in October ;2005 (with the help of the Mars Global Surveyor ), is that these bands suggest plate tectonic activity on Mars four billion years ago, before the planetary dynamo ceased to function and the planet's magnetic field faded. The Phoenix lander returned data showing Martian soil to be slightly alkaline and containing elements such as magnesium , sodium , potassium and chlorine . These nutrients are found in soils on Earth. They are necessary for growth of plants. Experiments performed by
28350-560: The path splits at the so-called "Portezuelo del Inca". One continues to the summit, the other to a plateau at 6715 m elevation. Another set of protecting walls and small buildings form another waystation at 6550 m elevation. Two enclosures and a 11 m × 6 m platform are on the plateau, forming the highest archaeological site on Earth. The Inca roads connect with the major north–south Inca road that runs between San Pedro de Atacama and Copiapo . Infrastructure such as road markers, shelters and tambos are found along
28539-619: The plume, and new volcanoes are created where the plate advances over the plume. The Hawaiian Islands are thought to have been formed in such a manner, as has the Snake River Plain , with the Yellowstone Caldera being part of the North American plate currently above the Yellowstone hotspot . However, the mantle plume hypothesis has been questioned. Sustained upwelling of hot mantle rock can develop under
28728-614: The precipitation falls in summer and the other half in winter, crosses the Andes at Llullaillaco. It and the Atacama Desert owe its existence to the rainshadow effect of the Andes, air subsidence within South Pacific High , and the cold Humboldt Current off the Pacific coast. Owing to the high evaporation rates and low precipitation, the soils at Llullaillaco are among the driest on Earth. The climate has not always been uniformly dry. Between 14,000 and 9,500 years ago during
28917-551: The previously mentioned plants. Above this altitude, plant cover decreases again, probably due to low temperatures, and disappears above 5000 m elevation; most of the volcano lies above this line. Deyeuxia curvula , Distichia muscoides and Oxychloe andina form wetlands ( bofedales ) in valleys. The fauna is represented by deer , guanacos , vicuñas and vizcachas . Especially around waterbodies are birds like ducks, flamingos and rheas . Most animals do not reach altitudes above 4600 m . A scorpion species
29106-566: The radiation of 1.84 millisieverts per day or 22 millirads per day during the flight to and from Mars. For comparison the radiation levels in low Earth orbit , where Earth's space stations orbit, are around 0.5 millisieverts of radiation per day. Hellas Planitia has the lowest surface radiation at about 0.342 millisieverts per day, featuring lava tubes southwest of Hadriacus Mons with potentially levels as low as 0.064 millisieverts per day, comparable to radiation levels during flights on Earth. Although better remembered for mapping
29295-488: The region and possibly all of the Central Andes, and the complex of archaeological sites is one of the most significant in the Andes. In the case of Llullaillaco, they may have been sites of pilgrimage used by the local Atacama people during Inca rule , no evidence of pre-Inca activity has been found. About forty-five structures have been identified at Llullaillaco, distributed across several sites and with clear architectonic differences, implying not all of them were built by
29484-521: The release of water and other volatile material from the subducting plate, which is then injected into the above-lying mantle wedge . The volcanic zones are separated by gaps, where subduction occurs at a flatter angle due to the presence of ridges on the downgoing plate: The Nazca Ridge in the gap between the NVZ and CVZ, the Juan Fernandez Ridge in the one between the CVZ and SVZ, and
29673-456: The road close to Llullaillaco. The paths on Llullaillaco are not simple footpaths but equipped with retaining walls, delimited edges and above "Portezuelo del Inca" with staircases. They were built by the Inca, their construction methods perhaps reflecting Inca mythology. They were discovered by Mathias Rebitsch in 1958. Llullaillaco appears to have been the most important Inca sacred mountain in
29862-407: The same pathway, and magma interacted with the crust as it ascended. The depth of the magma source probably varied over the history of the volcano. The total magma output at Llullaillaco is about 0.05 cubic kilometres per millennium (0.012 cu mi/ka)- 0.02–0.04 km/ka . The climate in the region is cold, dry and sunny. There are only limited climate data from Llullaillaco. Temperatures at
30051-435: The same time interval. Volcanoes vary greatly in their level of activity, with individual volcanic systems having an eruption recurrence ranging from several times a year to once in tens of thousands of years. Volcanoes are informally described as erupting , active , dormant , or extinct , but the definitions of these terms are not entirely uniform among volcanologists. The level of activity of most volcanoes falls upon
30240-492: The same way; they are often described as "caldera volcanoes". Submarine volcanoes are common features of the ocean floor. Volcanic activity during the Holocene Epoch has been documented at only 119 submarine volcanoes, but there may be more than one million geologically young submarine volcanoes on the ocean floor. In shallow water, active volcanoes disclose their presence by blasting steam and rocky debris high above
30429-467: The size of Earth's Arctic Ocean . This finding was derived from the ratio of protium to deuterium in the modern Martian atmosphere compared to that ratio on Earth. The amount of Martian deuterium (D/H = 9.3 ± 1.7 10 ) is five to seven times the amount on Earth (D/H = 1.56 10 ), suggesting that ancient Mars had significantly higher levels of water. Results from the Curiosity rover had previously found
30618-622: The solidified erupted material that makes up the mantle of a volcano may be stripped away that its inner anatomy becomes apparent. Using the metaphor of biological anatomy , such a process is called "dissection". Cinder Hill , a feature of Mount Bird on Ross Island , Antarctica , is a prominent example of a dissected volcano. Volcanoes that were, on a geological timescale, recently active, such as for example Mount Kaimon in southern Kyūshū , Japan , tend to be undissected. Eruption styles are broadly divided into magmatic, phreatomagmatic, and phreatic eruptions. The intensity of explosive volcanism
30807-422: The south polar ice cap, if melted, would be enough to cover most of the surface of the planet with a depth of 11 metres (36 ft). Water in its liquid form cannot prevail on the surface of Mars due to the low atmospheric pressure on Mars, which is less than 1% that of Earth, only at the lowest of elevations pressure and temperature is high enough for water being able to be liquid for short periods. Water in
30996-461: The southern highlands include detectable amounts of high-calcium pyroxenes . Localized concentrations of hematite and olivine have been found. Much of the surface is deeply covered by finely grained iron(III) oxide dust. Although Mars has no evidence of a structured global magnetic field , observations show that parts of the planet's crust have been magnetized, suggesting that alternating polarity reversals of its dipole field have occurred in
31185-498: The state. Among the structures are stone circles and roofed buildings. Archeological sites are also found in the valleys that drain Llullaillaco towards the Salar de Punta Negra, including the Quebrada Llullaillaco and the Quebrada de las Zorritas where the Inca paths ascend the mountain. The complex of archaeological sites has become subject of scientific research. Archaeological sites on mountains are widespread in
31374-505: The study of Mars. Smaller craters are named for towns and villages of the world with populations of less than 100,000. Large valleys are named for the word "Mars" or "star" in various languages; smaller valleys are named for rivers. Large albedo features retain many of the older names but are often updated to reflect new knowledge of the nature of the features. For example, Nix Olympica (the snows of Olympus) has become Olympus Mons (Mount Olympus). The surface of Mars as seen from Earth
31563-401: The summit are about −15 °C (5 °F)-−13 °C (9 °F), with temperature maximums ranging from −8 °C (18 °F) in summer to −13 °C (9 °F) in winter. The temperature of the ground fluctuates strongly between day and night, and can reach 12.5 °C (54.5 °F) in summer. The climate is extremely sunny, perhaps one of the sunniest places on Earth, and UV radiation
31752-513: The surface. However, later work suggested that the lineae may be dry, granular flows instead, with at most a limited role for water in initiating the process. A definitive conclusion about the presence, extent, and role of liquid water on the Martian surface remains elusive. Researchers suspect much of the low northern plains of the planet were covered with an ocean hundreds of meters deep, though this theory remains controversial. In March 2015, scientists stated that such an ocean might have been
31941-430: The surface. "Dena" is the only exception; its floor is visible and was measured to be 130 metres (430 ft) deep. The interiors of these caverns may be protected from micrometeoroids, UV radiation, solar flares and high energy particles that bombard the planet's surface. Mars lost its magnetosphere 4 billion years ago, possibly because of numerous asteroid strikes, so the solar wind interacts directly with
32130-406: The surrounding areas, and initially not seismically monitored before its unanticipated and catastrophic eruption of 1991. Two other examples of volcanoes that were once thought to be extinct, before springing back into eruptive activity were the long-dormant Soufrière Hills volcano on the island of Montserrat , thought to be extinct until activity resumed in 1995 (turning its capital Plymouth into
32319-625: The swelling of the Tharsis area, which caused the crust in the area of Valles Marineris to collapse. In 2012, it was proposed that Valles Marineris is not just a graben , but a plate boundary where 150 kilometres (93 mi) of transverse motion has occurred, making Mars a planet with possibly a two- tectonic plate arrangement. Images from the Thermal Emission Imaging System (THEMIS) aboard NASA's Mars Odyssey orbiter have revealed seven possible cave entrances on
32508-434: The theory of plate tectonics. For example, some volcanoes are polygenetic with more than one period of activity during their history; other volcanoes that become extinct after erupting exactly once are monogenetic (meaning "one life") and such volcanoes are often grouped together in a geographical region. At the mid-ocean ridges , two tectonic plates diverge from one another as hot mantle rock creeps upwards beneath
32697-444: The thinned oceanic crust . The decrease of pressure in the rising mantle rock leads to adiabatic expansion and the partial melting of the rock, causing volcanism and creating new oceanic crust. Most divergent plate boundaries are at the bottom of the oceans, and so most volcanic activity on Earth is submarine, forming new seafloor . Black smokers (also known as deep sea vents) are evidence of this kind of volcanic activity. Where
32886-608: The trenches. Others have medium contents of potassium. Phenocrysts are mostly hornblende or pyroxene with lesser quantities of biotite and quartz ; apatite , iron-titanium oxides, opaque minerals, sphene , sulfides and zircon are rare. Some phenocrysts show evidence of a complex history. Older rocks contain hematite . Elemental sulfur is found at Llullaillaco, specifically at Azufrera Esperanto; sulfur reserves are estimated to amount to 210,000 tonnes (210,000 long tons; 230,000 short tons). Trace element data are typical for Central Volcanic Zone rocks. Rocks become more felsic
33075-431: The underlying ductile mantle , and most volcanic activity on Earth takes place along plate boundaries, where plates are converging (and lithosphere is being destroyed) or are diverging (and new lithosphere is being created). During the development of geological theory, certain concepts that allowed the grouping of volcanoes in time, place, structure and composition have developed that ultimately have had to be explained in
33264-507: The upper mantle of Mars, represented by hydroxyl ions contained within Martian minerals, is equal to or greater than that of Earth at 50–300 parts per million of water, which is enough to cover the entire planet to a depth of 200–1,000 metres (660–3,280 ft). On 18 March 2013, NASA reported evidence from instruments on the Curiosity rover of mineral hydration , likely hydrated calcium sulfate , in several rock samples including
33453-492: The volcano. Solid particles smaller than 2 mm in diameter ( sand-sized or smaller) are called volcanic ash. Tephra and other volcaniclastics (shattered volcanic material) make up more of the volume of many volcanoes than do lava flows. Volcaniclastics may have contributed as much as a third of all sedimentation in the geologic record. The production of large volumes of tephra is characteristic of explosive volcanism. Through natural processes, mainly erosion , so much of
33642-424: The volcanoes of the East African Rift . A volcano needs a reservoir of molten magma (e.g. a magma chamber), a conduit to allow magma to rise through the crust, and a vent to allow the magma to escape above the surface as lava. The erupted volcanic material (lava and tephra) that is deposited around the vent is known as a volcanic edifice , typically a volcanic cone or mountain. The most common perception of
33831-420: The widespread presence of crater lakes across a large proportion of the surface, for which there is independent mineralogical, sedimentological and geomorphological evidence. Further evidence that liquid water once existed on the surface of Mars comes from the detection of specific minerals such as hematite and goethite , both of which sometimes form in the presence of water. In 2004, Opportunity detected
34020-433: The world ( Ojos del Salado is the highest). In the early 20th century, Llullaillaco was thought to be the highest volcano in the world. The elevation is to a large degree consequence of the underlying terrain, which rises about 4 km above sea level. The height of the mountain and the clear air in the region make Llullaillaco visible from Cerro Paranal , 190 km away as measured through Google Maps . The view from
34209-587: The younger they are: Older rocks contain more quartz and biotite than recent ones, and display higher iron and lower alkali metal contents. The composition may reflect magma differentiation in a solitary magma chamber , but with occasional replenishment with more primitive/ differentiated melts. Processes in the chamber such as magma mixing and plagioclase crystallization yielded melts with homogeneous composition and low volatile concentrations that upon eruption formed viscous lava flows. A lithospheric structure probably directed magma flows over long time periods along
34398-531: Was built on terraces and partly buried by loose debris from the mountain above. Two water sites lie between the cemetery and the tambo . An Inca ceremonial path begins at the tambo and leads up the volcano. It is 1.5–2 m wide (narrower in steeper reaches) and marked by wooden posts and cairns , probably for the case that the path is covered in snow. It continues past two waystations at 5600 m and 6300 m elevation, which consist of small buildings and protecting walls. At 6500 m altitude,
34587-421: Was described by Roman writers as having been covered with gardens and vineyards before its unexpected eruption of 79 CE , which destroyed the towns of Herculaneum and Pompeii . Accordingly, it can sometimes be difficult to distinguish between an extinct volcano and a dormant (inactive) one. Long volcano dormancy is known to decrease awareness. Pinatubo was an inconspicuous volcano, unknown to most people in
34776-525: Was discovered in the lake. The microorganisms in the lake resemble these of other Central Andean lakes, such as Aguas Calientes and Lake Licancabur , in some ways and differ in others. Species-poor fungal and bacterial communities have been found in the soils (more precisely: tephra ) of Llullaillaco, with the fungus Naganishia friedmanii being the most common species. The soils are extremely poor in organic matter and have simple ecological communities. They have to survive environmental conditions among
34965-412: Was during the late glacial when the climate was moister. Periglacial phenomena are observed on Llullaillaco, commencing at 4300 m altitude and reaching their maximum around 5100–5400 m on the Chilean and 5350–5700 m on the Argentine side. They are solifluction surfaces, cryoplanation surfaces, block ramparts, and patterned ground . Permafrost is found at higher altitudes and
35154-495: Was inhabited by hunters and shepherds in pre-Hispanic times. At some point between 1470 and 1532 CE , the Inca empire occupied the region. There are numerous abandoned mines in the region, and the active lithium production plant "Proyecto Mariana" at Salar de Llullaillaco. Azufrera Esperanto is an abandoned sulfur mine north of Llullaillaco and is associated with an area of hydrothermal alteration. The mine can be reached through
35343-416: Was once believed that Llullaillaco had experienced three large glaciations, but the " moraines " are actually mudflow /volcanic deposits. Some landforms indicate that any glaciation occurred before the last glacial maximum . Even when temperatures decreased during the last glacial maximum , the climate at Llullaillaco may have been too dry to permit glacier development. If any glacier expansion took place, it
35532-629: Was probably the root cause of the incision in almost all cases. Along craters and canyon walls, there are thousands of features that appear similar to terrestrial gullies . The gullies tend to be in the highlands of the Southern Hemisphere and face the Equator; all are poleward of 30° latitude. A number of authors have suggested that their formation process involves liquid water, probably from melting ice, although others have argued for formation mechanisms involving carbon dioxide frost or
35721-437: Was reported that InSight had detected and recorded over 450 marsquakes and related events. Beneath the crust is a silicate mantle responsible for many of the tectonic and volcanic features on the planet's surface. The upper Martian mantle is a low-velocity zone , where the velocity of seismic waves is lower than surrounding depth intervals. The mantle appears to be rigid down to the depth of about 250 km, giving Mars
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